vhost_kern/vdpa: fix get_iova_range()
vhost_kern/vdpa: fix get_iova_range()

A wrong ioctl request was used in get_iova_range().
Unfortunately, there was no test, otherwise the ioctl would fail.

Let's fix this by using the right ioctl request.
We also add a test by checking the values we expect from
a vDPA-block simulator that returns [0, u64::MAX] range.

Fixes  #106

Reported-by: Sebastien Boeuf <90b401417360b1924ef3f520ddee932686110f85@intel.com>
Signed-off-by: Stefano Garzarella <6f3dd2004310421c0dda1107f4857e62a774d5df@redhat.com>

rust-vmm/vhost